Color developers containing polyethylene glycols



United States Patent COLOR DEVELOPERS CONTAINING POLY- ETHYLENE GLYCOLS- Judith A. Schwan and Catherine Marilyn Spath, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y.., a corporation of New Jersey No Drawing. Filed Mar. 8, 1957, Ser. No. 644,744 1 Claim. (Cl; 96-55) This invention relatesv to photography and particularly toaccelerators for color developing solutions.

Multilayer reversal color films of the type described in Marines, Godowsky and Wilder U.S. Patent 2,252,718

are. developed first in a 'black-and-white developer, thenre-exposed through separation filters and color developed to form a subtractive dye image in each of the emulsion layers. There are two important problems in connection withthe first color development step, that is, the cyan development of the red-sensitive emulsion layer. First, the desired maximum cyan density must be obtained in the exposed regions with a minimum of cyan fog in the unexposed areas (i.e., cyan development in the green-sensitive or blue-sensitive layers which have not been re-exposed). Any attempt to increase cyan D-max. such as by prolonged cyan development is usually accompanied by an increase in cyan fog. Second, all of the exposedsllver halide grainsfrom the first re-exposure' must be completely reduced before subsequent magenta and yellow development in order to avoid magenta or yellow contamination. of the cyan layer.

It is therefore an object of the present invention to prow'de a method and means for accelerating reversal color development. A further object is to provide a color development giving dye images of increased maximum density or'D-max. A still further object is to provide a methodfor increasing the density of. color developeddye images. Other objects will appear fromthe following description of our invention.

These objects are accomplished by incorporating in the color developer used to develop an exposed silver halide emulsion, especially an emulsion of a multilayer photographic element, a non-ionic or ionic polyethylene glycol as described hereinafter.

In the process of Mannes, Godowsky and Wilder U.S. Patent 2,252,718 a multilayer element is employed having red-sensitive, green-sensitive and blue-sensitive emulsion layers superimposed in that order on a support. The. emulsions do not contain color couplers but there is. a yellow filter layer between the blue-sensitive and green-sensitive emulsion layers. After exposure in the usual way, the film is developed in an ordinary blackancl-white developer. It is then exposed through the base to light passing through a red filter to re-expose only the red-sensitive layer, and this layer is developed to a cyan positive dye image in a primary aromatic amino developing solution containing a cyan-forming coupler. The remaining two emulsion layers are then successively exposed or rendered developable and developed in ap propriate color-forming developers, yellow for the bluesensitive emulsion and magenta for the green-sensitive emulsion. This produces positive dye images in each of the emulsion layers. All of the developed silver is then removed in a bleach which does not affect the dye images.

We have found that the maximum density of the dye images, especially the cyan dye image, may be increased in this process by incorporating a non-ionic or iomc Patented Aug.. 30, 11960 tionare polymers derived from ethylene oxide. The

preparation of these. compounds is described in Ellis,

The Chemistry of Synthetic Resins (1935), pages 990 to 994. The polymers which we employ should have a molecular weight of at least 600since the lower molecular weight. polymers do not show any appreciable accelerating effect.

The following compounds are useful according to our invention; these being illustrative only:

NON-IONIC HO( C zc z 14CH2CH2OH Polyethylene glycolM.W. about 600 2) HO-(CH CH 0) CH CH OH Polyethylene g1ycolM.W. about 1500 (A useful polyethylene glycol is Carbowax 1540, a product of'Car-b-id'e and Carbon Chemicals Corporation, which has the formula HO(CH CH O) CH CH OH where n has an'averagevalue of 35. This polyethylene glycol is believed to be a mixture of compounds, and has an average molecular weight of 1300 to 1600,- a specific gravity of 1.15, a. freezing point of 43 to 46 C., a viscosity at 210 F. of 25 to 32 centistokes, a Cleveland Open Cup flash point of 510 F., and is by weight soluble in waterat 20 C.)

(3 HO (CH2CH2O CH CH OH Polyethylene g1ycolM.W. about 4000 CATIONIC (4) ri wnlcrm Terminals from polyethylene oxide of molecular weight 1540 Polyethoxyethylbls-carb0glutamic acid (sodium salt) Compounds 4 to 6 and 8 are prepared as follows:

COMPOUND 4 v To 400 ml. of dry pyridine contained in a one-liter flask equipped with stirrer, thermometer, and dropping funnel was added 154 g. (0.1 mole) of Carbowax 1540. The solution was chilled to C. and 24 g. (0.20 mole +5 percent excess) of methane sulfonyl chloride was slowly added through thet dropping funnel so that the temperaturenever rose above 5 C. After stirring the slurry for two hours, the solution was allowed to warm up to room temperature while stirring an additional three hours. The slurry was acidified with 1:1 hydrochloric acid at 20 C., and the solution saturated with sodium chloride. The ester was extracted four times with 500-ml. portions of hot benzene. Concentration of the benzene extracts yielded 102 g. (59 percent) of a light yellow viscous oil which turned to a semi-solid upon standing, Carbowax l540-,w-bis(methanesulfonate) (the yield can be improved by extracting the ester continuously in a liquid-liquid extractor from the weakly acidic solution).

Fifty milliliters of dry pyridine and 44.4 g. (0.025 mole) of Carbowax 1540 ct,w bis (methanesulfonate), were heated gently on the steam bath for three hours at 90 C. An exothermic reaction occurred in the beginning of the reaction. The excess pyridine was removed completely on the steam bath under vacuum, leaving a tan semisolid, Carbowax l540-a,w-bis-(pyridinium methanesul-.

fonate) COMPOUND 5 Sixteen and six-tenths grams (0.01 mole) of Carbowax 1540-a,w-bis(methanesulfonate), and 3.8 g. (0.02 mole) of triethanolamine were added together. The two layers were heated to 120-130" C. with vigorous stirring for one hour. A clear, uniform, pale yellow oil was obtained weighing 18.5 g. (91 percent) which solidified upon cooling. The product gave a clear foaming solution when dissolved in water.

COMPOUND 6 In a flask equipped with a drying tube and sealed stirrer, 77 parts of Carbowax 1540 were dissolved in 250 parts of dry benzene. The temperature was adjusted to C. with a cooling bath, and 27.4 parts of 3,5-disulfonyl chloride chlorobenzene were added. The reaction was allowed to warm to room temperature in an hour; during this time the complete solution resulted. Heat was applied and reflux was maintained for 4 to 5 hours, after which the solvent and evolved hydrochloric acid were removed by distillation at reduced pressure.

With water jet cooling, 65 parts of distilled water were added from a droping funnel, care being taken not to exceed 25 C. A solution of 32 parts of sodium hydroxide in 80 parts of distilled water was added at 5-15 C. in small portions. Stirring was continued for an hour. The mixture was diluted to a total weight of 539 parts for a 20 percent aqueous solution and was gravity filtered before use.

COMPOUND 8 A mixture of 151 g. of Carbowax 4000 and g. of dimethyl isocyanatoglutarate was heated at 70 C. for hours, protected from atmospheric moisture. The resulting product was treated gradually with 6 g. of sodium hydroxide in 15 ml. of water. The mixture was heated at 60-70 C. for 3 hours, water being added occasionally to maintain the product in a fluid state. It was finally diluted with water to a total weight of 332 g. The resulting solution contained an estimated 166 g. of

solid. The water can be removed from the product to yield a pale yellow solid.

Compound 7 is prepared as described in Carroll, Elins, Graham and Wilson application Serial No. 627,136.

Our invention will now be illustrated by reference to the following specific examples:

Example 1 A high-speed gelatino-silver bromoiodide emulsion containing 0.24 mole of silver halide per liter was digested with a sulfur compound such as disclosed in Sheppard U.S. Patent 1,574,944 and potassium chloroaurate and optically sensitized to red light. To a portion of this emulsion there was added 0.66 gram per gram mole of silver halide of the condensation product of one mole of oleyl alcohol with approximately 25 moles of ethylene oxide (polyethylene glycol oleyl ether). These emulsions were separately coated on film base and were exposed on an Eastman type Ib sensitometer and developed for 3 minutes at 70 F. in a developer of the following" formula:

Grams- N-methyLp-aminophenol sulfate 0.6 Hydroquinone 20 Sodium sulfite (desiccated) 50 Sodium bromide 6.88 Sodium thiocyanate 6 Sodium hydroxide 20 Potassium iodide Water to 1 liter.

After a two-minute wash in water, the films were flashed for 10 seconds with a No. 2 Reflector Photoflood 5 feet away. .The portions of the films were then de-v veloped for from 3 to 5 minutes at F. in a cyan developer of the following composition and also in thissame developer to which 1 gram per liter of several.

of the polyethylene glycols had been added:

Water to 1 liter.

After a ten-minute water wash, films were bleached for two minutes in a solution having the following com- Water to 1 liter.

After a further .water rinse, the films were then fixed,

for two minutes in asolution of the following composition:

Sodium thiosulfate-5H O grams 240 Sodium sulfite (desiccated) do '15 Acetic acid (28% solution) cc 48 'Boric acid grams 7.5 Potassium alum do 15 Water to 1 liter.

'A second set of film strips was processed in exactly the same manner except that the flash re-exposure was I omitted.

p The maximum cyan dye density and the cyan fog were I then read through a complementary color filter and each of the samples and the results tabulated as follows:

Coatings were made and processed as in Example 1 except that a magenta developer was used instead of the cyan developer, and Carbowax 1540 was the only compound tested in this developer. The results for maximum magenta density and magenta fog when read through a complementary color filter are tabulated below. The magenta developer had the following composition:

Grams 2-amino-5-diethylamino toluene HCl 1.5 Sodium sulfite (desiccated) 5 Sodium hexametaphosphate 0.5 Sodium carbonate, monohydrate Sodium bromide 0.22 Potassium iodide 0.002 6-nitrobenzimidazole nitrate 0.01 Sodium hydroxide 1.7 2-cyanoacetyl coumarone 0.5 Water to 1 liter.

The results are shown in the following table:

Emulsion without Emulsion contain- PEG ing PEG Daveloper Addenda Magenta Magenta Magenta Magenta D-ma.x. Fog D-max. Fog

0. 7 1. 0. 61 Fa;;a;1saa'ziti7is:::.-.. 68 .63 1. 60 .60

Example 3 The eifect of the polyethylene glycols in a p-phenylene diamine developer containing a yellow coupler was also investigated. Development acceleration was noted with no increase in maximum color density but with shorter development time required for producing equal maximum densities. With the emulsion coating of Examples 1 and 2 containing the polyethylene glycol oleyl ether a maximum density of 1.45 at fog of 0.65 was attained after five minutes in the color developer containing w-benzoylacet-(p-toluene sulfonamido) anilide as the yellow coupler. These same values were attained with the developer containing the polyethylene glycol after only four minutes development.

It will be understood that the above examples are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

A photographic color developer capable of producing dye images of increased dye density with no increase of color fog upon color development of a silver halide emulsion, comprising a developing solution separate from said emulsion, containing an alkylamino paraphenylenediamine color developer, a coupler compound capable of coupling with the oxidation product of said developer to form a dye upon photographic development, and a polyethyleneglycol selected from the group consisting of (1) polyethylene glycols having the formula HO(CH CH 0),,CH CH OH where n is from 14 to 85, (2) polyethoxyethyl-bispyridinium methane sulfonate, and (3) polyethoxyethylbis-sulfuric acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,366,737 Loder et a1. Ian. 9, 1945 2,531,832 Stanton Nov. 28, 1950 2,716,062 Carroll et a1 Aug. 23, 1955 2,772,162 Salminen et a1. Nov. 27, 1956 

